This invention relates to a marine trap of the type used to trap shrimp, crabs, lobsters and other types of relatively small marine animals. The particular disclosure of this application is for a trap designed especially for trapping shrimp and, with minor modifications, lobster and crab. However, it will be understood that the trap is used for catching virtually any type of marine life which can be induced to enter the trap.
Historically, shrimp have been harvested from the ocean by means of large nets. Typically, these nets are suspended on outboard booms and towed through relatively shallow water by large, powerful trawlers. The nets drag along the sea floor for a specified period of time after which they are raised and the contents collected. This method of shrimp harvesting is relatively expensive and inefficient for numerous reasons. First, dragging for shrimp with nets is limited to relatively flat, smooth sea bottom in order to prevent the nets from tearing and snagging. Also, nets must be used only in relatively shallow water.
Large, powerful boats are required to tow the nets through the water for long periods of time before they are raised and the contents collected.
Nets will sweep up any and all objects in its path, including not only shrimp and other types of sea life but rocks, mud, shells and debris. When the contents of the net are dumped into the boat, all of this undesirable material must be sorted from the shrimp and thrown overboard. Furthermore, the shrimp may themselves be packed under tons of rock, shells and fish and therefore may be broken, crushed or otherwise damaged. Pieces of shrimp and damaged whole shrimp typically bring a much lower price than do undamaged shrimp.
Finally, the drag nets themselves are large and very expensive. They need constant repair since they are quite often torn by rocks and other objects which they may encounter while being dragged across the sea floor.
For all these reasons, shrimp trapping is becoming a more economically feasible means of harvesting shrimp.
Many traps can be set from a relatively small boat. The traps can be dropped into areas having a rocky or uneven seafloor--places where most shrimp live. Most sorting can be eliminated and a higher quality of shrimp can be delivered to market.
Shrimp are currently trapped by using one of a relatively few types of shrimp traps. Some are similar to lobster traps in that they are constructed of wooden slats with a hinged top opening with serpentine entrances through which the shrimp can enter but not easily exit. This type of trap is relatively heavy and since they cannot be nested together for storage, take up a substantial amount of deck space on a boat. For this reason, a relatively large boat must be used or the number of traps being laid at any one time must be limited.
Other known shrimp traps are similar to oversized egg cartons. They are constructed of plastic material and hinged on one side with holes formed in the plastic to permit water to drain out. This type of trap has a fixed-size mouth with rigid, breakable teeth angled into the interior of the trap to keep the shrimp from exiting. While these traps can be nested when open, they require a large winch to recover since the water drains from them relatively slowly. Also, the teeth are breakable and the mouth is of a single size which cannot be adjusted to accommodate trapping for different sized marine animals. Also, the traps are relatively expensive to make and to repair.